This invention relates to a reduced insertion force multi contact electrical connector having a plurality of superposed rows of contacts of a mating connector. The invention also relates to a pair of contact elements for such a reduced insertion force connector.
The concept of staggering the contact surfaces of the contact elements of a printed circuit edge connector in the mating direction of the printed circuit board, thereby to reduce the force needed to mate the circuit board with the connector is disclosed in U.S. Pat. No. 3,193,791; U.S. Pat. No. 3,818,280; U.S. Pat. No. 4,200,349; U.S. Pat. No. 4,343,523; U.S. Pat. No. 4,636,021 and U.S. Pat. No. 4,842,538. Such printed circuit edge connectors do not, however, comprise a plurality of rows of pairs of contact elements and excepting in the case of the connectors disclosed in U.S. Pat. No. 4,343,523 and U.S. Pat. No. 4,200,349 the contact surfaces of the contact elements of one row are staggered with respect to the contact surfaces of the contact elements of the other row, not only in the mating direction but also lengthwise of the connector. There is disclosed in U.S. Pat. No. 3,793,609, a zero insertion force connector in which a printed circuit board is engaged by two pairs of contact elements in each of a plurality of transverse compartments in a housing. The contact surfaces of the contact elements of each pair are offset from each other in the direction of insertion of the printed circuit board, but the contact surfaces of both the longer and the shorter contact elements lie opposite to each other. Zero insertion force is achieved by means of an actuator which cams the pairs of contact elements in each compartment apart from each other for insertion of the circuit board.
A multicontact electrical connector having a plurality of superposed rows of pairs of contact elements for mating with superposed rows of contacts of a mating connector, may comprise between 300 and 400 contact elements. It is, therefore, desirable, not only that the force needed to mate the connectors should be reduced, but that the normal force exerted against each of the individual contact elements should be as far as possible uniform.